Numerical modelling of the Young’s modulus of syntactic foams

Syntactic foams are particulate composites obtained by filling a polymeric matrix with hollow solid inclusions. Numerical simulations are an important tool to predict material behaviour and optimize the mechanical properties. The aim of this work is to develop a multi-phase numerical model to predict stiffness of the syntactic foams. The numerical parameters were identified and optimized, and the numerical predictions were validated with experimental results from 3-point bending tests. Different physical parameters were then studied, namely the volume fraction and the size of the filler, the elastic properties of filler and matrix and the inclusion's thickness. A sensitivity analysis was developed to quantify the importance of these different parameters, and the rigidity of the matrix was found to be the most influent. The parametric space was scanned and a numerical interpolation procedure implemented based on shape functions of finite element method. The procedure is an interesting tool for design and was used to identify the particles having stiffness equal to the matrix.